Internal combustion engine



y 5 1970 H. DEUTSCHMANN 1-rrm.

INTERNAL COMBUSTION ENGINE 2 Sheets-Sheet 1 Filed June 14, 1968INVENTORS HERBERT DEUTSCHMANN JUERGEN WAHNSCHAFFE BY WOLFGANG RUDERT vnos ATTORNEYS May 1970 H. DEU'ESCHMANN E 'AL 3,509,861

INTERNAL COMBUSTION ENGINE INVEN'IORS HERBERT DEUTSCHMANN JUERGENVIAHNSCHAFFE BY WOLFGANG RUDERT HERBERT MAUER ATTORNEYS United StatesPatent O 1,576,35 Int. C1. Flm 1/10;F16n 39/06 U.S. C]. 123196 15 ClaimsABSTRACT OF THE DISCLOSURE An internal combustion engine in which thelubricant line system between the crankcase and the suction pump for thelubricant has a line portion which determines the level at which agas-free suction can be obtained; the upper edge 0f the free lubricantflow cross section is arranged in this line portion lower than thecorresponding edge at the sieve for cleaning the lubricant to be sucked01T.

The present invention relates to an internal cornbustion engine, andmore particularly to a line system be tween the sump of the crankcaseand the suction pump for the lubricant.

The aim underlying the present invention essentiafly resides in beingable to get along wtih a 10W lubricant level in the crankcase of aninternal combustion engine, especially having a dry-sump lubrication, sothat the bottom part of the crankcase can be designed lower, i.e., oflesser height. This particularly flat construction of the crankcase ofan internal combustion engine is required, for example, for the driveunit in modern combattype vehicles. Notwithstanding the 10W type ofconstruction, a sufliciently large sieve cross section for the cleaningof the lubricant to be sucked out of the sump has to be available.

The underlying roblems are solved according to the present invention inthat the lubricant line system between the sump of the crankcase and thelubricant suction pump includes a line section or line ortion,determining the level for a gas-free sucking-ofi of the lubricant, inwhich the upper edge of the free lubricant passage cross section isarranged lower than the corresponding edge at the sieve for the cleaningof the lubricant to be sucked off. The advantage is achieved by thepresent invention that it is possible even with a minirnum lubricantlevel in the crankcase to provide gas-free suct1on.

In one embodiment of the present invention, the leveldetermining linesection or line portion may be arranged in the suction channel of thecrankcase. Fo-r this purpose, the suction channel may be provided at itsupper wall part With a downwardly directed projection.

With this embodiment, the sieve can close as cover- 0r lid-like body thedischarge aperture of the lubricant line system on the side of the sumpand may be designed suitably large within the frame of the availablespace, independently of the type of construction of the leveldeterminingline portion.

According to another feature of the present invention, it is proposedthat the level-determining line section is constituted by a suctionconnection enlarged in cross section in a funnel-like manner, in whichthe lower aperture terminates in the sump and the higher aperture isconnected to the lubricant line system. The advantage results from suchan arrangement that the sump level can be kept particularly 10W by theflat design of the aperture 0f the suction connection on the side of thesump without the drawback of sucking otf any air. A further advantage ofthis proposed construction according to the present invention resides inthat the aperture of the suction connection on the sump side can bearranged within a part of the lubricant sump, that is relatively calmand quieted from a streamline or flow point 0f view so that the pressurelosses of the pump are reduced.

In order to be able to accommodate particularly large sieve surfaces,the sieve body for the cleaning Of the lubricant to be sucked off can bearranged at an inclination to the level of the lubricant sump.

Appropriately, the sieve is arranged downstream of the suctionconnection and can then be secured together with the suction connectionat the crankcase.

It is further proposed according to the present inven tion that theaperture of the suction connection terminating in the sump extends inthe shape of a circular arc. If one arranges the connecting place of thesuction line at the suction connection in the center point or inproximity to the center point of the imaginary arc, then a very even anduniform suction effect is achieved within every area of the aperture onthe side of the sump.

Accordingly, it is an object of the present invention to provide aninternal combustion engine With sump lubrication that avoids theaforementioned shortcomings and drawbacks encountered in the prior artby simple and operationally reliable meana Another object of the presentinvention resides in an internal combustion engine which is able tooperate with a relatively 10W lubricant level in the crankcase in orderto be able to reduce the height of the bottom part of the crankcase.

A further object of the present invention resides in an internalcombustion engine of the type described above which makes available asufliciently large sieve cross section for the cleaning of the lubricantto be sucked out of the sump.

Still another object of the present invention resides in a lubricatingsystem for internal combustion engines in which a gas-free suction canbe achieved even with a minimal lubricant level in the crankcase.

A still further object of the present invention resides in an internalcomb1istion engine with sump lubrication in which pressure losses of thesuction pump can be effectively reduced.

These and further objects of the present invention Will become moreobvious from the following description when taken in connection with theaccompanying drawing which shows, for purposes of illustration only,several embodiments of suction places in crankcases With drysumplubrication according to the present invention and wherein:

FIG. 1 is a partial longitudinal cross-sectional view through the end onthe flywheel side of a crankcase bottom part in accordance with thepresent invention;

FIG. 2 is an elevational view taken in the direction of arrow II of FIG.1;

FIG. 3 is a partial cross-sectional view through a modified embodimentof the end on the flywheel side of a crankcase bottom part in accordanceWith the present invention;

FIG. 4 is a schematic plan view of the end on the flywheel side 0f astill further modified embodiment of a crankcase bottom part accordingto the present invention;

FIG. 5 is a plan view on the suction connection as individual part ofthe arrangement according to FIG. 4; and

FIG. 6 is a side elevational view of the suction place 3 illustratedinFIG. 4 and taken in the direction of arrow VI.

Referring now to the drawing wherein like reference numerals are usedthroughout the various views to designate like parts, and moreparticularly to FIGS. 1 and 2, reference numeral 100 generallydesignates therein The front end on the flywheel side of the crankcasebottom part which includes the housing end Wall 102 and the housingbottom 103. A lubricant suction channel 101 is cast integral with thehousing end Wall 102 and the hausing bottom 103 and extends transverselyto the housing longitudinal axis. The suction channel 101 includes atits upper Wall part 104 a downwardly directed projection 105. The oilsump wetting the housing bottom 103 is delimited by a transverse Wallgenerally designated =by reference numeral 106 of the suction channel101 which is inclined to the level of the oil sump at least in thenormal position of the crankcase. The suction channel 101 is incommunication With the oil sump by way of a funnelshaped channelaperture 107. The inner discharge 108 of the channel aperture 107 isdelimited in the upward direction by the bottom edge 109 of theprojection 105. A minimum oil level S is given by the bottom edge 109,with which oil can be sucked out of the sump essentially without suckingout any aiI-, gasor vapor-particles.

The outer discharge 110 of the channel aperture 107 is delimited in theupward direction by an edge 111 whose significance Will be furtherexplained in the following description.

The outer discharge aperture 110 is adapted to be covered by a sivebody, essentially Z-shaped in cross section, which is indicated in dashand dot lines at 112 and is t be secured at the Wall part 106 at 113 bymeans of bolts (not shown).

The free lubricant passage or flow cross section of the sieve body 112is defined or delimited in the upward direction by the edge 111, whencean oil level S is determined.

Since the edge 109 according to the present invention is arranged lowerthan the edge 111, an ever-increasing sieve surface for the passage ofthe oil to be sucked off is available with an oil level increasingbetween S and S This. action is independent from the arrangement of thesieve body 112 both with respect to the oil level as also with respectto the projection 105. This means, the sieve body 112 can be arranged,on the one band, either perpendicularly or also inclined to the oillevel and, on the other, either upstream or downstream of thelevel-determining projection 105.

In the embodiment according to FIG. 3, which is similar to that of FIGS.1 and 2, the crankcase bottom part generally designated by referencenumeral 300 together with the cast-on suction channel 301 is indicatedonly in dash and dot lines.

The oil sump wetting the housing bottom 303 is in communication With thesuction channel 301 by way of a suction connection enlarged in afunnel-like manner and generally designated by reference numeral 314, ofa sieve body 312 essentially X-shaped in cross section, and by way of achannel aperture 307. The cross section of the channel 301 is delimitedby the housing end Wall 302, The housing bottom 303, an upper Wall part304, as well as a transverse wall generally designated by referencenumeral 306 and arranged inclined to the oil level. The suctionconnection 314 together witl1 the sieve body 312 can be secured in afluid-tight manner at the channel Wall 306 at 313 by means of bolts. Thelower aperture 315 of the suction connection 314 which is also smallerin cross section, terminates in the oil sump Whereas the larger aperture316 of the connection 314 is in communication with the channel aperture307. The upper edge 317 of the smaller, lower aperture 315 on the sideof the sump in the suction connection 314 determines the lowest oillevel S at which an air or gas-free suckingoil of the oil is assured.

The upper boundary of the free assage 01' flow cross section in thesieve body 312 is indicated by reference numeral 318. An oil level Scorresponds to the level of this edge 318. When the oil level increasesbetween the pegs S and S an ever-increasing sieve surface is availablefor the cleaning of the oil to be sucked off. In this embodiment, thesuction connection 314 is arranged upstream 0f the sieve body 312. Inorder to be able to accommodate a particularly large sieve surfacewithin the available 10W interior space of the crankcase bottom part300, the sieve body 312 is again arranged inclined to the oil level inthe normal position. The prevailing oil level is thereby to be assumedto extend normally substantiafly horizontally.

In the embodiment of FIGS. 4 to 6, the crankcase bottom part isgenerally designated by reference numeral 400, the cast-on suctionchannel by reference numeral 401, the housing end Wall by referencenumeral 402, and the housing bottom by reference numeral 403.

The oil sump wetting the housing bottom 403 is in communication with thesuction channel 401 by way of asuction connection 414 enlarged in afunnel-like manner, of a sieve body 412 essentiafly Z-shaped in crosssection and by way of a channel aperture 407.

The cross section of the suction channel 401, in addition to beingdelimited by the end Wall 402 and the housing bottom 403, isadditionally delimited by an upper channel Wall 404 and by a channelWall 406 inclined to the oil level and provided With the channelaperture 407.

The suction connection 414 together with the sieve body 412 can besecured in a fluid-tight manner at the channel Wall 406 at 413 by rneansof b0lts (not shown). The lower aperture 415 of the suction connection414 extends along a circular arc a and terminates in the oil sumpwhereas the higher aperture 416 of the connection 414 is incommunication with the channel aperture 407. The center point of the arca is located in proximity to that part of the discharge place of thelubricant at the suction connection which is disposed closest to thesuction pump in the direction of flow.

The diifering pressure conditions at the sieve surface can be equalizedby this type of construction of the suction connection 414. For the Samereason, that part of the aperture 415 on the side of the sump can beincreased which is disposed in proximity to the area of the sieve body412 located farthest removed from the mentioned center point. Thesuction pressure of the lubricant pump is considerably lower within thisarea cf the sieve body 412. As a result of the enlarged aperture area ofthe suction connection 414 on the side of the sump, this pressuredecrease is then properly taken into consideration for purposes ofachieving a uniform oil suction eflect.

As can be readily seen from FIG. 6, the lowest oil level S is determinedby the upper edge 417 of the aperture 415 on the side of the sump withwhich an airfree suction of the lubricant is still assured. The upper.edge 418 of the free flow cross section at the sieve body 412 determinesan oil level S Since the edge 417 is again arranged lower than the edge418, a larger sieve cross section is available for the cleaning of thesucked off lubricant. When the oil level increases between IS and S thesieve cross section traversed by the oil also increases.

While we have shown and described several embodiments in accordance withthe present invention, it is understood that the same is not limitedthereto but is suscepble of numerous changes and modifications as knownto a person skilled in the art.

Wo claim:

1. An internal co=mbustion engine with a crankcase and a lubricantsuction pump, wherein the improvement comprises lubricant line meansbetween the sump of the crankcase and the lubricant suction pump whichincludes sieve means for cleaning the lubricant to be sucked off andmeans for determining the level for [a substantially gasfree suctionoperation, said level-determining means being located in a suctionchannel means of the crankcase and providing in effect a free lubricantflow cross-section having an upper edge which is arranged lwer than thecorresponding edge at said sieve means.

2. An internal combustion engine with a crankcase and a lubricantsuction pump, wherein the improvement comprises lubricant line meansbetween the sump of the crankcase and the lubricant suction pump whichincludes sieve means for cleaning the lubricant to be sucked off andmeans for determining the level for a substantially gasfree suctionoperation, said level-determining means being formed, at least in part,by a suction connection enlarged in a funnel-like manner and havinglower and upper apertures, the lower aperture terminating in the sumpand the upper aperture being connected with said lubricant line means.

3. An internal combustion engine according to claim l, wherein saidsuction channel means of the crankcase includes an upper wall parthaving a downwardly directed projection.

4. An internal combustion engine according to claim 1, wherein thedischarge of the lubricant line means to the sump is formed by a very Waperture which is very wide in relation to its height.

5. An internal combustion engine according to claim 2, wherein the bodyof sieve means for the cleaning of the lubricant to be sucked off isarranged at an inclination to the level of the lubricant sump in normalposition.

6. An internal combustion engine according to claim 5, wherein the sievemeans is arranged downstream of the suction connection.

7. An internal combustion engine according to claim 6, wherein theaperture of the suction connection discharging in the sump extends inthe form of a substantially circular arc.

8. An internal combustion engine according to claim 7, wherein said lineportion is arranged in a suction channel means of the crankcase.

9. An internal combustion engine according to claim l, Wherein the bodyof sieve means for the cleaning of the lubricant to be sucked 011 isarranged at an inclination to the level of the lubricant sump in normalosition.

10. An internal combustion engine according to claim 2, wherein thesieve means is arranged downstream of the suction connection.

11. An internal combustion engine according to claim 10, wherein theaperture of the suction connection discharging in the sump extends inthe form of a substantially circular arc.

12. An internal combustion engine according to claim 11, wherein thedischarge of the lubricant line means to the sump is formed by a very10W aperture which is very wide in relation to its height.

13. An internal combustion engine according to claim 2, wherein theaperture of the suction connection discharging in the sump extends inthe form of a substantially circular arc.

14. An internal combustion engine according to claim 2, wherein thedischarge of the lubricant line means to the sump is formed by a very10W aperture which is very wide in relation to its height.

15. An internal combustion engine according to claim 4, wherein saidsuction channel means cf the crankcase includes an upper wall parthaving a downwardly directed projection.

References Cited UNITED STATES PATENTS 1638,281 8/1927 Winslow et a1I846 1'903005 3/1933 McCuen 184--6 1939765 12/1933 Church I846 21924383/1940 Gulick 184-6 2536,663 1/1951 Schaer 184-6 XR 3,056501 10/1962Thorman et a1. 123-196 XR 3,143,187 8/1964 Stefan I846 MILTON KAUFMAN,Primary Examiner M. A. ANTONAKAS, Assistant Examiner U.S. C1. X.R. I846

